Food of various kinds, including sliced deli meats, sausage, cheese and bacon, are frequently sliced in high volume automated slicing machines, wherein the food products are cut into slices and transported in portions for further processing, such as weighing and packaging. Slicing machines such as the one disclosed in U.S. Pat. No. 4,548,108, and other machines capable of continuous high volume output, can be used.
Food industry regulation of labeling practices requires precise weight measurements of food corresponding to the package label. To ensure that consumers receive packaged goods reflecting the weight shown on the label, it is necessary to weigh the food product carefully before packaging. However, the process of weighing sliced food product can be time consuming, and calculating the additional slices needed to reach the desired weight limits the efficiency of the manufacturing process.
In many cases, food manufacturers err on the side of caution and end up packing more, by weight, of the food product so as not to fall short of the weight requirement. This additional weight is referred to as the give-away weight. Processing food slices so as to minimize the give-away weight poses numerous challenges, due to the often irregular shape of various food types. Food types, especially meats, can be irregularly shaped, and can have progressive variations in density, unexpected changes in composition, or changes in other parameters, sometimes as a result of temperature dependent conditions.
U.S. Pat. Nos. 3,099,304; 3,667,520; 4,065,911; and 4,545,447 disclose methods and apparatus for stacking and weighing slices of cut food products. U.S. Pat. No. 6,640,681 relates to a method and a device that allows portions of similar slices to be obtained even if the product that is sliced is changed.
U.S. Pat. No. 3,099,304 discloses an apparatus for stacking and weighing sliced food products, and controlling the weight of the stacks produced. The apparatus is initially set to receive a certain number of slices. The slices are deposited on a stacker turret which rotates when a certain period of time has elapsed and a given number of slices have been deposited. Stacks are transferred to a conveyer mounted on a stack to check-weigh the stack. The apparatus uses a feed-back control mechanism for the check-weigher to the feed control of the slicing machine in order to vary the speed of the feed mechanism when the stack of slices is overweight or underweight.
U.S Pat. No. 3,667,520 discloses a slicer control system comprising a weight monitoring system for comparing the weight of the slices cut against a predetermined standard. The weight monitoring system prematurely actuates a take-away conveyor when a predetermined error exists even though the predetermined ecmber of slices has not yet been cut, in order to minimize the number of groups of slices having gross errors that would result in rejection for weight deviations from the standard.
U.S. Pat. No. 4,065,911 discloses a combination bacon slicing, segregating and weighing apparatus which is designed to interrupt the feeding mechanism when slices are at a weight less than prescribed. The apparatus provides for weighing, counting and registering the weight of the light weight group, and calculates a new feed rate which will produce a number of whole slices at the right thickness in making up the added weight to produce the draft target weight.
U.S. Pat. No. 4,545,447 provides an apparatus for stacking and weighing slices of cold cuts. A scale is positioned with respect to the stacker to register the weight after a preselected amount of slices are collected on the stacker.
The present inventors have recognized that known prior art slicing and weighing apparatus and methods described, and others, have been disadvantageous for various reasons. The additional step of weighing the sliced food product is often time consuming and may require stopping the slicer or stopping the conveyor belts. Furthermore, the step of determining the additional amount of product needed to meet the target weight, and completing the slices, is also time consuming. There is a need to increase the economic efficiency of slicing and weighing sliced food products. The method and apparatus of the present invention allows for more efficient slicing and weighing of the food product, and provides a calibration of processing parameters after each weighing of the final draft product to ensure fine tuned accuracy of each following draft.